Piston for internal combustion engines



Marh 8, 1938. A;'M.'ALEXANDRESCU PISTON FOR INTERNAL COMBUSTION E ENGIIiES 2 Sheets-Sheet l Fil ed Aug. -6, 1935 Fig.1.

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PISTON FOR INTERNAL COMBUSTION ENGINES March 8, 1938.

Filed Aug. 6, 1935 2 sheets-sheaf 2 3nventor J1 M u lxandrescu/ Patented Mar. s, 1938 UNITED STATES PATENT; orrlca PISTON FOR INTERNAL COMBUSTION ENGINES Alexander M. Alcxamlrescu, Cleveland, Ohio Application AugustoI 1935, Serial No. 35,001

r 2 Claims. .(01. 309-8) The present invention relates to a new and novel construction of piston for internal combustion engines and has for an object to provide an improved type of piston having an upper section to mount the compression rings and one or more oil rings to register with openings in the upper section for passing oil from within the piston therethrough, and to likewise serve for the escape of the oil during the operation of the piston in assuring the proper compression and the release of any smoke or raw gas passed below the compression rings through the openings into the piston to drive the oil downwardly inside thereof. Another object of the present invention resides in providing a skirt formed in sections adapted to be connected together along with the upper section to form slots or grooves between the sections for the passage of oil from within the piston to engage the cylinder wall, whereby a film of oil for keeping these parts lubricated at all speeds of the engine is attained to assure perfect compression and greater power, and to prevent scar ring of the piston in any manner.

A further object of the new piston construction is to provide a new oil and pressure discharging system for the passage of clean oil between the piston and cylinder wall to form a cooling medium for the piston along with the rings and to prevent the usual collection of car-' 30 bon thereon.

Another object of the new device is to permit the usage of one or more small sized oil rings, and an arrangement of openings cut radially through the piston to communicate with the oil ring grooves and to project substantially half of their width above the rings, whereby the oil may be more freely and advantageously passed back and forth therethrough from the interior ofthe 4 piston.

oil passedthroughthe skirt portions thereof, and top'ermitffor' a-greater clearance between each mg better compression;

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A further object of the new piston is to providea means for lubricating all of the pistons with Figure 2 is a transverse section taken along the line 22 of Figure 1..

' v Figure 3 is a central vertical section through a slightly modified form of the piston.

Figure 4 is a transverse section taken along the line 4-4 of Figure 3.

Figure 5 is acentral vertical section through another type of slightly modified form of the piston.

-Figure 6 is a transverse section taken along 10 the line 6-6 of Figure 5; t

Figure '7 is-a front elevation of a further modified form of the piston.

Figure 8 is a central vertical section taken along the"line 8-8 of Figure '7. 15

Figure 9 is a transverse section taken line 9-9 of Figure '7.

Flgure 10 is a transverse section taken along the line ill-i0 of Figure I. p

Figure 11 is a fragmentary vertical another modified form of the piston, and

Figure 12 is a fragmentary view taken along the line i2-l2 of Figure 11.

Referring to the drawings and more particularly to the form of the invention disclosed in Figures 1 and 2 the numeral ill designates the usual cylinder of an internal combustion engine of any suitable type in which the new construction of piston ii is mounted to operate.

along the The piston is advantageously and readily formed to provide sections in which the upper section I2 is shaped to present an'inverted cylindrical cup with a closed upper'enjd ll'andhaving the interior I thereof cut away to form an outer and downwardly extending wall I 5." This wall l5 is spaced slightly from the cyiinderwallf lii; and is provided with a' plurality'of peripheral grooves it along the upper 'portionthere'of forinserting the compression rings i'l oi a; type such "as -n6w-' commonly employed whereby waa'am' lie" do sired compression in thecylinderi p Ms as ers or n widtntn reams i ares-.

ii to register with th e lowermost groove section of 20 inside the piston underthe pressure of the raw gas and smoke.

These openings assure the passage of clean oil to pass therethrough from the interior of the piston to engage the cylinder wall and to be returned during the proper and desired operation of the piston.

The lower portion of the wall I5 has formed thereon'the downwardly projecting lugs is which are spaced apart, and engage the inner wall of the top section or sleeve 20. The upper edge of the sleeve is held rigidly by the lugs or connection members I8 in spaced relation to the lower edge of the wall l5 to form a series of slots or grooves 2| connected together and to provide a continuous circumferential passageway 2|a for the lubricating oil to flow from the interior of the piston to contact with the cylinder wall. This assures a means for readily cooling the upper section or sleeve 20 by the flow of the oil back and forth from the crank case during the operation of the piston.

The intermediate sleeve 22 is rigidly held along its upper edge in spaced relation to the lower edge of the top sleeve 20 by connections or lugs 23 to provide a series of slots or grooves 24 connected together to form the continuous passageway 24a.

The lower sleeve 25 is also held in a similar manner by lugs 23 along its upper edge to the lower edge of the intermediate sleeve 22 in spaced relation to form the grooves or slots 26 and to provide the continuous passageway 28a.

The oilfrom the inner portion of the piston likewise passes through the series of slots 24 and 26 arranged along these two circumferential levels to evenly and completely distribute the oil to contact with the cylinder wall whereby to more efllciently cool the piston.

The upper section l2 of the piston is also provided along the lower edge of the wall IS with a pair of elongated lugs 21 arranged in diametrically disposed relation, and to project downwardly into contact with all of the sleeves or skirt sections. These lugs 21 are secured to these sections and afford an additional means for securely holding the skirt sections in proper alinement. The trunnions 2! are formed upon the lugs 21 and are cut therethrough with openings 29 adapted to support a wrist pin. The series of grooves or slots 24 are advantageously arranged and alined with the openings 29 whereby to afford means for supplying lubricating oil to the wrist pin.

The form of the piston shown in Figures 3 and 4 shows a slightly modified construction wherein the skirt sections are preferably cut to form a vertical slot 30 which provides a passageway to connect the circumferentially arranged grooves- J the splash of oil from the bearings within the skirt sections. and thus prevent too much oil going into the upper section and passing therethrough about the rings.

A furthermore modified type of the piston is disclosed in Figures 5 and 6. The upper skirt section 3 I and the lower skirt section 32, are secured together'and held to the upper section I: by

practically the samurrangement of connect ons or lugs as previously described. The skirt seethe skirt sections, and at the same time bring the oil into contact with the wrist pin.

Referring more particularly to the form of the piston shown in Figures '7 to 10 the elongated openings 34 are formed to pass through the piston wall in diametrically disposed relation and placed 4 intermediate the top and the bottom of'the skirt portion of the piston. The small circumferential grooves 34 connect with the openings 38 and permit the oil passed from the interior of the piston to circulate uniformly all around the piston and in contact with the cylinder wall. These grooves are advantageously placed within the skirt of the piston for performing-the lubrication of the parts since it is readily appreciated that the piston can be titted within the cylinder with very small clearance," This lends towards keeping the rings steady, for compression, and attains greater coolingresults.

The type of piston shown in Figures 7 to 10 can be made with a round skirt as shown, and if desired slightly oval shaped but not sufficient to be intelligently shown on the drawings without ex aggerating the same. When the oval shaped type of skirt is formed the diametrically disposed portions of the skirt at right angles to the trunnions presents the elongated or widest portion of the skirt. This portion will contact with the cylinder wall without any clearance, and in having the elongated holes 33 formed in this portion of the skirt the oil is fed therethrough to contact with the cylinder wall to keep the parts properly lubricated.

The piston shown in Figures 11 and 12 shows a different type of connection 25 for holding the upper section and the skirt sections properly spaced apart and in alinement. tions are preferably rounded adjacent their upper and lower edges 2 to engage with the circumferentially arranged grooves or slots to direct the oil from the crank case more readily and efficiently therethrough for uniformly cooling the skirt sections and the rings. The pair of oil rings 31 are of a smaller size than the comprestions are preferably spaced further apart to form These skirt secsion rings arid are mounted below the same with c the openings ll cut through the piston to register and to project beyond the oil ring grooves. These openings ll afford an ei'licient means for the passage of oil from-within the piston into the oil grooves and to contact with the cylinder wall. The oil is returned through the openings to the inside of the piston around the rings by the force of the raw gas and smoke which is passed downwardly by the compression rings from the engine. 7

Having thus described my invention what I claim and desire to secure by Letters Patent 01 the United States is:-

1. A piston for internal combustion engines pgsilfg'a'closed top, a ring column having inner and outer walls, said ring column having compression ring grooves and an oil ring groove openradial depththan the oil ring groove whereby to leave ample top wall surface for the oil ring groove against which the oil ring engages at its upper side, such top wall surface being continuous all around the piston for the stable support of the oil ring at all points, said ring column having a port substantially radially therethrough opening through both inner and outer walls ofthe ring column and communicating at its outer side with both the undercut portion and the bottom of the oil ring groove.

2. A piston for internal combustion engines comprising a closed top, a ring column having inner and outer walls, said ring column having compression ring grooves and an oil ring groove opening through the outer wall, compression and oil rings in said grooves, said ring column having a portion of its outer wall undercut just above the oil ring groove, the undercut portion extending uninterruptedly annularly around said piston and forming an annular chamber just above the oil ring, said undercut portion being of much less radial depth than the oil ring groove whereby to leave ample top wall surface for the oil ring groove against which the oil ring engages at its upper side, such top wall surface being continuous all around the piston for the stable support of the oil ring at all points, said ring column having a port substantially radially therethrough opening through both inner and outer walls of the ring column and communicating at its outer side with both the undercut portion and the bottom of the oil ring groove, a skirt extending in spaced relation to said ring column, and connectors spaced aboutthe circumference of the piston for joining said ring column and skirt, said ring column and skirt having an annular oil channel therebetween for holding oil splashed up from the crankcase,

ALEXANDER M. ALEXANDRESCU. 

